kubernetes pod升级与回滚扩容与缩容

运行一个容器：

apiVersion: apps/v1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "1"
  creationTimestamp: "2020-09-19T02:41:11Z"
  generation: 1
  labels:
    app: nginx
  name: nginx
  namespace: default
spec:
  progressDeadlineSeconds: 600
  replicas: 3              # 副本数
  revisionHistoryLimit: 10 # 历史记录保留的个数
  selector:
    matchLabels:
      app: nginx
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:1.15.4
        imagePullPolicy: IfNotPresent
        name: nginx
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30

# 保存为deployment.yaml 并创建nginx pod：
[root@k8s-master01 yaml]# kubectl create -f  deployment-nginx.yaml
deployment.apps/nginx created

#检查：
[root@k8s-master01 yaml]# kubectl get pod
NAME                     READY   STATUS    RESTARTS   AGE
nginx-6cdd5dd489-d7kll   1/1     Running   0          17s
nginx-6cdd5dd489-dblw2   1/1     Running   0          17s
nginx-6cdd5dd489-zc8fl   1/1     Running   0          17s

#检查nginx版本：
[root@k8s-master01 yaml]# kubectl exec -it nginx-6cdd5dd489-d7kll -- sh
# nginx -v
nginx version: nginx/1.15.4

镜像升级与回滚

#升级：
root@k8s-master01[11:10:24]:~/yaml$ kubectl set image deploy nginx nginx=nginx:1.15.5 --record=true
deployment.apps/nginx image updated

#检查升级过程：
kubectl describe  pod nginx-7c4b6d99fd-csh5s

Events:
  Type    Reason     Age   From               Message
  ----    ------     ----  ----               -------
  Normal  Scheduled  76s   default-scheduler  Successfully assigned default/nginx-df9789dc8-6h7p7 to k8s-node02
  Normal  Pulling    76s   kubelet            Pulling image "nginx:1.15.5"
  Normal  Pulled     51s   kubelet            Successfully pulled image "nginx:1.15.5" in 24.828362289s
  Normal  Created    51s   kubelet            Created container nginx
  Normal  Started    51s   kubelet            Started container nginx

#检查现在的版本：
[root@k8s-master01 yaml]# kubectl exec -it nginx-df9789dc8-trtwq -- sh 

# nginx -v
nginx version: nginx/1.15.5

#检查更新过程
kubectl rollout status deploy nginx

[root@k8s-master01 yaml]# kubectl rollout status deploy nginx
Waiting for deployment "nginx" rollout to finish: 1 out of 2 new replicas have been updated...
Waiting for deployment "nginx" rollout to finish: 1 out of 2 new replicas have been updated...
Waiting for deployment "nginx" rollout to finish: 1 out of 2 new replicas have been updated...
Waiting for deployment "nginx" rollout to finish: 1 old replicas are pending termination...
Waiting for deployment "nginx" rollout to finish: 1 old replicas are pending termination...
deployment "nginx" successfully rolled out

[root@k8s-master01 yaml]# kubectl exec -it nginx-6cdd5dd489-bsb7f -- sh
# nginx -v
nginx version: nginx/1.15.5

#为了实验效果 在升级一次
[root@k8s-master01 yaml]# kubectl set image deploy nginx nginx=nginx:1.15.6 --record=true

[root@k8s-master01 yaml]# kubectl get pod
NAME                     READY   STATUS    RESTARTS   AGE
nginx-5455fbc855-64brv   1/1     Running   0          2m48s
nginx-5455fbc855-nblks   1/1     Running   0          3m16s
nginx-5455fbc855-ns4kz   1/1     Running   0          2m47s
[root@k8s-master01 yaml]# kubectl exec -it nginx-5455fbc855-64brv -- sh
# nginx -v
nginx version: nginx/1.15.6

#回滚：
1. 查看历史更新
kubectl rollout history deploy nginx

[root@k8s-master01 yaml]# kubectl rollout history deploy nginx
deployment.apps/nginx
REVISION  CHANGE-CAUSE
1         <none>
2         kubectl set image deploy nginx nginx=nginx:1.15.5 --record=true
3         kubectl set image deploy nginx nginx=nginx:1.15.6 --record=true

2. 回滚到上一个版本[kubectl rollout undo deploy {name} ]
[root@k8s-master01 yaml]# kubectl rollout undo deploy nginx
deployment.apps/nginx rolled back

3. 检查回滚状态：
[root@k8s-master01 yaml]# kubectl get pod
NAME                     READY   STATUS    RESTARTS   AGE
nginx-6cdd5dd489-bzdgd   1/1     Running   0          21s
nginx-6cdd5dd489-cwxv5   1/1     Running   0          22s
nginx-6cdd5dd489-xb6xj   1/1     Running   0          20s

3.1 进入容器检查：
[root@k8s-master01 yaml]# kubectl exec -it nginx-6cdd5dd489-bzdgd -- sh
# nginx -v
nginx version: nginx/1.15.4

4. 回滚到指定版本
[root@k8s-master01 yaml]# kubectl rollout history deploy nginx
deployment.apps/nginx
REVISION  CHANGE-CAUSE
1       kubectl set image deploy nginx nginx=nginx:1.15.5 --record=true
2       kubectl set image deploy nginx nginx=nginx:1.15.6 --record=true

# 查看指定版本信息
kubectl rollout history deploy nginx --revision=1

#回滚到指定版本
 kubectl rollout undo deploy nginx --to-revision=1

 [root@k8s-master01 yaml]# kubectl exec -it nginx-6cdd5dd489-q44cr -- sh
 # nginx -v
 nginx version: nginx/1.15.5

使用pod扩容，缩容

[root@k8s-master01 yaml]# kubectl get pod
NAME                    READY   STATUS    RESTARTS   AGE
nginx-df9789dc8-gqk5j   1/1     Running   0          11m
nginx-df9789dc8-vhqkd   1/1     Running   0          11m

#修改资源：
[root@k8s-master01 yaml]# kubectl edit deploy nginx
deployment.apps/nginx edited

找到： replicas: 2
改为： replicas: 3

#检查状态：
[root@k8s-master01 yaml]# kubectl get pod
NAME                    READY   STATUS    RESTARTS   AGE
nginx-df9789dc8-c47mc   1/1     Running   0          3s
nginx-df9789dc8-gqk5j   1/1     Running   0          11m
nginx-df9789dc8-vhqkd   1/1     Running   0          11m

#缩容就是继续把 replicas: 3 改为： replicas: 2即可：
[root@k8s-master01 yaml]# kubectl get pod
NAME                    READY   STATUS    RESTARTS   AGE
nginx-df9789dc8-gqk5j   1/1     Running   0          13m
nginx-df9789dc8-vhqkd   1/1     Running   0          13m

使用yaml文件进行升级

apiVersion: apps/v1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "1"
  creationTimestamp: "2020-09-19T02:41:11Z"
  generation: 1
  labels:
    app: nginx
  name: nginx
  namespace: default
spec:
  progressDeadlineSeconds: 600
  replicas: 3              # 副本数
  revisionHistoryLimit: 10 # 历史记录保留的个数
  selector:
    matchLabels:
      app: nginx
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: nginx
    spec:
      containers:
      - image: nginx:1.15.4
        imagePullPolicy: IfNotPresent
        name: nginx
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30

#修改：
    spec:
      containers:
      - image: nginx:1.15.5    #改为想要的镜像版本

#改为 1.15.5
[root@k8s-master01 yaml]# kubectl apply -f nginx-1.yaml
deployment.apps/nginx configured
[root@k8s-master01 yaml]# kubectl get pod

#注意升级的时候 他会起新的rs(replicas),通过命令可以看到，他会新起来一个pod 并把老副本数设置为2，新副本起来2个的时候
#老副本数会设置为1，直到变成0 最后才会真正的完成滚动更新。
[root@k8s-master01 yaml]# kubectl get rs
NAME               DESIRED   CURRENT   READY   AGE
nginx-5455fbc855   3         3         3       4m46s
nginx-565979ccb4   1         1         0       5s

[root@k8s-master01 yaml]# kubectl get pod
NAME                     READY   STATUS    RESTARTS   AGE
nginx-5455fbc855-j552c   1/1     Running   0          17s
nginx-5455fbc855-sl8m8   1/1     Running   0          15s
nginx-5455fbc855-sq4mr   1/1     Running   0          14s
[root@k8s-master01 yaml]# kubectl exec -it nginx-5455fbc855-j552c  -- sh
# nginx -v
nginx version: nginx/1.15.5

## 查看滚动更新过程：
NewReplicaSet:   nginx-565979ccb4 (3/3 replicas created)
Events:
  Type    Reason             Age                     From                   Message
  ----    ------             ----                    ----                   -------
  Normal  ScalingReplicaSet  10m                     deployment-controller  Scaled up replica set nginx-6cdd5dd489 to 3
  Normal  ScalingReplicaSet  9m53s                   deployment-controller  Scaled up replica set nginx-df9789dc8 to 1
  Normal  ScalingReplicaSet  9m51s                   deployment-controller  Scaled down replica set nginx-6cdd5dd489 to 2
  Normal  ScalingReplicaSet  9m51s                   deployment-controller  Scaled up replica set nginx-df9789dc8 to 2
  Normal  ScalingReplicaSet  9m50s                   deployment-controller  Scaled down replica set nginx-6cdd5dd489 to 1
  Normal  ScalingReplicaSet  9m50s                   deployment-controller  Scaled up replica set nginx-df9789dc8 to 3
  Normal  ScalingReplicaSet  9m48s                   deployment-controller  Scaled down replica set nginx-6cdd5dd489 to 0
  Normal  ScalingReplicaSet  7m47s                   deployment-controller  Scaled up replica set nginx-5455fbc855 to 1
  Normal  ScalingReplicaSet  7m45s                   deployment-controller  Scaled down replica set nginx-df9789dc8 to 2
  Normal  ScalingReplicaSet  2m18s (x10 over 7m45s)  deployment-controller  (combined from similar events): Scaled down replica set nginx-5455fbc855 to 0